Abstract: A method of manufacturing a zinc oxide powder including synthesizing a mesoporous zinc oxide precursor powder by adding an aqueous solution of zinc chloride to an aqueous solution of sodium carbonate while agitating to cause precipitation of a mesoporous zinc carbonate powder wherein the molar ratio of zinc chloride to sodium carbonate present when the aqueous solution of zinc chloride and the aqueous solution of sodium carbonate are reacted is at least 1:2, heat treating a mesoporous zinc precursor material to form the mesoporous zinc oxide powder at a heat treatment temperature in the range of 250-575° C. The zinc oxide powder includes mesoporous zinc oxide aggregates with a plurality of primary zinc oxide crystallites bonded together at shared interfaces.

Abstract: A process for the production of nanorods containing a rare earth metal is disclosed. The process comprises the steps of: (a) increasing the pH of an aqueous solution of the formula MX3, where M is a trivalent rare earth metal cation and X is a monovalent anion so as to produce a reaction product containing X anions in solution and a precipitate in the form of trivalent rare earth hydroxide nanoparticles of the formula M(OH)3, the nanoparticles having a hexagonal crystal structure; and, (b) ageing the nanoparticles of step (a) in the presence of the reaction product containing X anions in solution so as to cause rod-like anisotropic growth of the nanoparticles and form rare earth hydroxide nanorods.

Abstract: A broad-spectrum UV photoprotective composition is described. The composition is characterized in that the composition comprises mesoporous zinc oxide aggregates having an average aggregate size of at least 0.8 microns dispersed in a carrier and the composition is visibly transparent. Sufficient zinc oxide is included in the composition to achieve an SPF greater than 15, greater than 25, greater than 30, or greater than 50.

Abstract: A zinc oxide powder is described, which, when used in a dispersion at a concentration of at least 50 wt % of zinc oxide, produces a transparent composition having a total visible transmittance through a path length of 20 microns at 550 nm of at least one of; at least 70%, at least 75%, at least 80% or at least 85%. The powder has a number average zinc oxide aggregate size of at least 0.8 microns, at least 1 micron, at least 2 microns or at least 3 microns. Use of the zinc oxide powder reduces the risk of transdermal penetration.